Information:
When Elvis first wore the "Thunderbird", he didn't wear it with the belt that was originally designed for it. He wore it with a belt that he got as a present from the hawaii'an actor Jack Lord. The suit was used with the original belt when Elvis wore it again in 1973.
When you compare the suit Elvis is wearing on all the known pictures, to the one that is on display at Graceland nowadays, there is a difference. The head of the bird is completely different... which would either mean that there were two slightly different versions of the suit, or the head of the bird was altered (ie. nail's added) when Elvis wore the suit for the last time(s) in 1973 (in Las Vegas August/September??)
The original belt, and the cape are in private hands. Elvis himself gave them to a young boy, dressed in a jumpsuit like Elvis', during the show on June 30th, 1973.
This is the only known suit that has kickpleats lined with stones(!).

The actual suit is owned by EPE/Graceland, but as mentioned above, the original belt and cape are still in private hands.